<html>
<head>
    <script type="text/javascript">
        function getCookie(c_name) {
            if (document.cookie.length > 0) {
                c_start = document.cookie.indexOf(c_name + "=")
                if (c_start != -1) {
                    c_start = c_start + c_name.length + 1
                    c_end = document.cookie.indexOf(";", c_start)
                    if (c_end == -1) c_end = document.cookie.length
                    return unescape(document.cookie.substring(c_start, c_end))
                }
            }
            return ""
        }

        function setCookie(c_name, value, expiredays) {
            var exdate = new Date()
            exdate.setDate(exdate.getDate() + expiredays)
            document.cookie = c_name + "=" + escape(value) +
                ((expiredays == null) ? "" : ";expires=" + exdate.toGMTString())
        }

        function checkCookie() {
            username = getCookie('username')
            if (username != null && username != "") {
                alert('Welcome again ' + username + '!')
            } else {
                username = prompt('Please enter your name:', "")
                if (username != null && username != "") {
                    setCookie('username', username, 365)
                }
            }
            alert(document.cookie)
        }
    </script>
</head>

<body onLoad="checkCookie()">
</body>
</html>